1 files changed, 458 insertions, 0 deletions
diff --git a/contrib/less/mark.c b/contrib/less/mark.c
new file mode 100644
index 000000000000..cbb316f276e6
--- /dev/null
+++ b/contrib/less/mark.c
@@ -0,0 +1,458 @@
+/*
+ * Copyright (C) 1984-2021  Mark Nudelman
+ *
+ * You may distribute under the terms of either the GNU General Public
+ * License or the Less License, as specified in the README file.
+ *
+ * For more information, see the README file.
+ */
+
+
+#include "less.h"
+#include "position.h"
+
+extern IFILE curr_ifile;
+extern int sc_height;
+extern int jump_sline;
+extern int perma_marks;
+
+/*
+ * A mark is an ifile (input file) plus a position within the file.
+ */
+struct mark 
+{
+	/*
+	 * Normally m_ifile != IFILE_NULL and m_filename == NULL.
+	 * For restored marks we set m_filename instead of m_ifile
+	 * because we don't want to create an ifile until the 
+	 * user explicitly requests the file (by name or mark).
+	 */
+	char m_letter;           /* Associated character */
+	IFILE m_ifile;           /* Input file being marked */
+	char *m_filename;        /* Name of the input file */
+	struct scrpos m_scrpos;  /* Position of the mark */
+};
+
+/*
+ * The table of marks.
+ * Each mark is identified by a lowercase or uppercase letter.
+ * The final one is lmark, for the "last mark"; addressed by the apostrophe.
+ */
+#define NMARKS          ((2*26)+2)      /* a-z, A-Z, mousemark, lastmark */
+#define NUMARKS         ((2*26)+1)      /* user marks (not lastmark) */
+#define MOUSEMARK       (NMARKS-2)
+#define LASTMARK        (NMARKS-1)
+static struct mark marks[NMARKS];
+public int marks_modified = 0;
+
+
+/*
+ * Initialize a mark struct.
+ */
+	static void
+cmark(m, ifile, pos, ln)
+	struct mark *m;
+	IFILE ifile;
+	POSITION pos;
+	int ln;
+{
+	m->m_ifile = ifile;
+	m->m_scrpos.pos = pos;
+	m->m_scrpos.ln = ln;
+	m->m_filename = NULL;
+}
+
+/*
+ * Initialize the mark table to show no marks are set.
+ */
+	public void
+init_mark(VOID_PARAM)
+{
+	int i;
+
+	for (i = 0;  i < NMARKS;  i++)
+	{
+		char letter;
+		switch (i) {
+		case MOUSEMARK: letter = '#'; break;
+		case LASTMARK: letter = '\''; break;
+		default: letter = (i < 26) ? 'a'+i : 'A'+i-26; break;
+		}
+		marks[i].m_letter = letter;
+		cmark(&marks[i], NULL_IFILE, NULL_POSITION, -1);
+	}
+}
+
+/*
+ * Set m_ifile and clear m_filename.
+ */
+	static void
+mark_set_ifile(m, ifile)
+	struct mark *m;
+	IFILE ifile;
+{
+	m->m_ifile = ifile;
+	/* With m_ifile set, m_filename is no longer needed. */
+	free(m->m_filename);
+	m->m_filename = NULL;
+}
+
+/*
+ * Populate the m_ifile member of a mark struct from m_filename.
+ */
+	static void
+mark_get_ifile(m)
+	struct mark *m;
+{
+	if (m->m_ifile != NULL_IFILE)
+		return; /* m_ifile is already set */
+	mark_set_ifile(m, get_ifile(m->m_filename, prev_ifile(NULL_IFILE)));
+}
+
+/*
+ * Return the user mark struct identified by a character.
+ */
+	static struct mark *
+getumark(c)
+	int c;
+{
+	PARG parg;
+	if (c >= 'a' && c <= 'z')
+		return (&marks[c-'a']);
+	if (c >= 'A' && c <= 'Z')
+		return (&marks[c-'A'+26]);
+	if (c == '\'')
+		return (&marks[LASTMARK]);
+	if (c == '#')
+		return (&marks[MOUSEMARK]);
+	parg.p_char = (char) c;
+	error("Invalid mark letter %c", &parg);
+	return (NULL);
+}
+
+/*
+ * Get the mark structure identified by a character.
+ * The mark struct may either be in the mark table (user mark)
+ * or may be constructed on the fly for certain characters like ^, $.
+ */
+	static struct mark *
+getmark(c)
+	int c;
+{
+	struct mark *m;
+	static struct mark sm;
+
+	switch (c)
+	{
+	case '^':
+		/*
+		 * Beginning of the current file.
+		 */
+		m = &sm;
+		cmark(m, curr_ifile, ch_zero(), 0);
+		break;
+	case '$':
+		/*
+		 * End of the current file.
+		 */
+		if (ch_end_seek())
+		{
+			error("Cannot seek to end of file", NULL_PARG);
+			return (NULL);
+		}
+		m = &sm;
+		cmark(m, curr_ifile, ch_tell(), sc_height);
+		break;
+	case '.':
+		/*
+		 * Current position in the current file.
+		 */
+		m = &sm;
+		get_scrpos(&m->m_scrpos, TOP);
+		cmark(m, curr_ifile, m->m_scrpos.pos, m->m_scrpos.ln);
+		break;
+	case '\'':
+		/*
+		 * The "last mark".
+		 */
+		m = &marks[LASTMARK];
+		break;
+	default:
+		/*
+		 * Must be a user-defined mark.
+		 */
+		m = getumark(c);
+		if (m == NULL)
+			break;
+		if (m->m_scrpos.pos == NULL_POSITION)
+		{
+			error("Mark not set", NULL_PARG);
+			return (NULL);
+		}
+		break;
+	}
+	return (m);
+}
+
+/*
+ * Is a mark letter invalid?
+ */
+	public int
+badmark(c)
+	int c;
+{
+	return (getmark(c) == NULL);
+}
+
+/*
+ * Set a user-defined mark.
+ */
+	public void
+setmark(c, where)
+	int c;
+	int where;
+{
+	struct mark *m;
+	struct scrpos scrpos;
+
+	m = getumark(c);
+	if (m == NULL)
+		return;
+	get_scrpos(&scrpos, where);
+	if (scrpos.pos == NULL_POSITION)
+	{
+		bell();
+		return;
+	}
+	cmark(m, curr_ifile, scrpos.pos, scrpos.ln);
+	marks_modified = 1;
+}
+
+/*
+ * Clear a user-defined mark.
+ */
+	public void
+clrmark(c)
+	int c;
+{
+	struct mark *m;
+
+	m = getumark(c);
+	if (m == NULL)
+		return;
+	if (m->m_scrpos.pos == NULL_POSITION)
+	{
+		bell();
+		return;
+	}
+	m->m_scrpos.pos = NULL_POSITION;
+	marks_modified = 1;
+}
+
+/*
+ * Set lmark (the mark named by the apostrophe).
+ */
+	public void
+lastmark(VOID_PARAM)
+{
+	struct scrpos scrpos;
+
+	if (ch_getflags() & CH_HELPFILE)
+		return;
+	get_scrpos(&scrpos, TOP);
+	if (scrpos.pos == NULL_POSITION)
+		return;
+	cmark(&marks[LASTMARK], curr_ifile, scrpos.pos, scrpos.ln);
+	marks_modified = 1;
+}
+
+/*
+ * Go to a mark.
+ */
+	public void
+gomark(c)
+	int c;
+{
+	struct mark *m;
+	struct scrpos scrpos;
+
+	m = getmark(c);
+	if (m == NULL)
+		return;
+
+	/*
+	 * If we're trying to go to the lastmark and 
+	 * it has not been set to anything yet,
+	 * set it to the beginning of the current file.
+	 * {{ Couldn't we instead set marks[LASTMARK] in edit()? }}
+	 */
+	if (m == &marks[LASTMARK] && m->m_scrpos.pos == NULL_POSITION)
+		cmark(m, curr_ifile, ch_zero(), jump_sline);
+
+	mark_get_ifile(m);
+
+	/* Save scrpos; if it's LASTMARK it could change in edit_ifile. */
+	scrpos = m->m_scrpos;
+	if (m->m_ifile != curr_ifile)
+	{
+		/*
+		 * Not in the current file; edit the correct file.
+		 */
+		if (edit_ifile(m->m_ifile))
+			return;
+	}
+
+	jump_loc(scrpos.pos, scrpos.ln);
+}
+
+/*
+ * Return the position associated with a given mark letter.
+ *
+ * We don't return which screen line the position 
+ * is associated with, but this doesn't matter much,
+ * because it's always the first non-blank line on the screen.
+ */
+	public POSITION
+markpos(c)
+	int c;
+{
+	struct mark *m;
+
+	m = getmark(c);
+	if (m == NULL)
+		return (NULL_POSITION);
+
+	if (m->m_ifile != curr_ifile)
+	{
+		error("Mark not in current file", NULL_PARG);
+		return (NULL_POSITION);
+	}
+	return (m->m_scrpos.pos);
+}
+
+/*
+ * Return the mark associated with a given position, if any.
+ */
+	public char
+posmark(pos)
+	POSITION pos;
+{
+	int i;
+
+	/* Only user marks */
+	for (i = 0;  i < NUMARKS;  i++)
+	{
+		if (marks[i].m_ifile == curr_ifile && marks[i].m_scrpos.pos == pos)
+		{
+			if (i < 26) return 'a' + i;
+			if (i < 26*2) return 'A' + (i - 26);
+			return '#';
+		}
+	}
+	return 0;
+}
+
+/*
+ * Clear the marks associated with a specified ifile.
+ */
+	public void
+unmark(ifile)
+	IFILE ifile;
+{
+	int i;
+
+	for (i = 0;  i < NMARKS;  i++)
+		if (marks[i].m_ifile == ifile)
+			marks[i].m_scrpos.pos = NULL_POSITION;
+}
+
+/*
+ * Check if any marks refer to a specified ifile vi m_filename
+ * rather than m_ifile.
+ */
+	public void
+mark_check_ifile(ifile)
+	IFILE ifile;
+{
+	int i;
+	char *filename = get_real_filename(ifile);
+
+	for (i = 0;  i < NMARKS;  i++)
+	{
+		struct mark *m = &marks[i];
+		char *mark_filename = m->m_filename;
+		if (mark_filename != NULL)
+		{
+			mark_filename = lrealpath(mark_filename);
+			if (strcmp(filename, mark_filename) == 0)
+				mark_set_ifile(m, ifile);
+			free(mark_filename);
+		}
+	}
+}
+
+#if CMD_HISTORY
+
+/*
+ * Save marks to history file.
+ */
+	public void
+save_marks(fout, hdr)
+	FILE *fout;
+	char *hdr;
+{
+	int i;
+
+	if (!perma_marks)
+		return;
+
+	fprintf(fout, "%s\n", hdr);
+	for (i = 0;  i < NMARKS;  i++)
+	{
+		char *filename;
+		struct mark *m = &marks[i];
+		char pos_str[INT_STRLEN_BOUND(m->m_scrpos.pos) + 2];
+		if (m->m_scrpos.pos == NULL_POSITION)
+			continue;
+		postoa(m->m_scrpos.pos, pos_str);
+		filename = m->m_filename;
+		if (filename == NULL)
+			filename = get_real_filename(m->m_ifile);
+		if (strcmp(filename, "-") != 0)
+			fprintf(fout, "m %c %d %s %s\n",
+				m->m_letter, m->m_scrpos.ln, pos_str, filename);
+	}
+}
+
+/*
+ * Restore one mark from the history file.
+ */
+	public void
+restore_mark(line)
+	char *line;
+{
+	struct mark *m;
+	int ln;
+	POSITION pos;
+
+#define skip_whitespace while (*line == ' ') line++
+	if (*line++ != 'm')
+		return;
+	skip_whitespace;
+	m = getumark(*line++);
+	if (m == NULL)
+		return;
+	skip_whitespace;
+	ln = lstrtoi(line, &line);
+	if (ln < 1)
+		ln = 1;
+	if (ln > sc_height)
+		ln = sc_height;
+	skip_whitespace;
+	pos = lstrtopos(line, &line);
+	skip_whitespace;
+	cmark(m, NULL_IFILE, pos, ln);
+	m->m_filename = save(line);
+}
+
+#endif /* CMD_HISTORY */